Rich media are those that convey greater amounts of information, including social cues and social presence, which enhance understanding across a wide swath of situations, even those that are ambiguous, whereas lean media are those that convey less information, fewer social cues, less social presence, and have relatively limited communication.
Both lean and rich media are important and exist on a continuum. The richer media are more effective in situations with higher ambiguity, higher equivocality, and less clarity, while leaner media will be more effective in situations that are more straightforward.
